Hi witchymand, €10 is the charge as long as no call exceeds 1 hour.
Calls to 1850 numbers aren't part of the €10 charge. Neither are calls to 11811. From reading previous threads, I understand that calls to ISP's are excluded also. I'm on broadband, so I can't confirm this though.
I don't make many international calls, so I don't know how Euphony's charges compare to other providers.
There's an option to "buy" call minutes to mobile numbers. I buy 100 minutes a month which costs an extra €17. Unfortunately, any unused minutes aren't carried forward to the next bill. Besides this, it's great!!